Make sure index ranges outside of the GLint range are handled correctly. IndexRange uses size_t values but DrawCallParams::mFirstVertex is a GLint. This makes sure all casting is safe. BUG=864528 Change-Id: Iaa95019615af4d3f79b12bbcb0df13b44cb54339 Reviewed-on: https://chromium-review.googlesource.com/1140898 Reviewed-by: Geoff Lang <geofflang@chromium.org> Commit-Queue: Geoff Lang <geofflang@chromium.org>